Materials for golf balls are generally required to provide good performance in terms of shot feeling, flight distance, and productivity, and thus studies to improve flexibility, resilience, and fluidity, which affect these performance properties, are being made.
Ionomers of ethylene/acrylic acid copolymers, composites of polybutadiene rubber and zinc acrylate and the like have been suggested as such materials. Unfortunately, the ionomers have excellent fluidity and high resilience but have poor flexibility, while the composites have excellent flexibility and high resilience but have poor fluidity.